Many communication applications exist that require an end-user to purchase or lease equipment for use at a customer location to access communication services. For example, cable television systems commonly require the use of a set-top cable box at the customer location to provide customer access to the services of the cable television service provider. The customer located equipment is usually programmed or configured by the service provider in accordance with an agreed-upon service package purchased by the customer. For example, a cable television service provider may configure a set-top cable box so that it is only capable of providing certain channels to the customer based upon a contracted level of service purchased by the customer. To configure the customer-located equipment, the service provider will typically load and/or enable predetermined software and/or hardware within the equipment to activate the corresponding functionality.
As can be appreciated, the customer-located equipment is normally out of the physical control of the service provider. Thus, this equipment is particularly susceptible to incursion by hackers and others wishing to receive more than an agreed upon level of service. These hackers will commonly modify the customer-located equipment in a manner that allows additional features to be activated within the equipment or broader access rights to be had within the system. For example, a hacker may modify a set-top cable box so that it is capable of unscrambling cable channels which the customer has not paid for. Some hackers may even make modifications to the customer-located equipment that are designed to cause harm to the service provider or others. All such incursions are illegal and result in, at a minimum, a significant loss of revenue for the service provider.
Therefore, there is a need for a method and apparatus for verifying the integrity of remote units in a communication system.